首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21篇
  免费   1篇
林业   3篇
  6篇
综合类   1篇
农作物   2篇
水产渔业   2篇
畜牧兽医   7篇
植物保护   1篇
  2021年   1篇
  2018年   2篇
  2015年   1篇
  2013年   1篇
  2012年   1篇
  2011年   1篇
  2010年   2篇
  2009年   3篇
  2007年   3篇
  2006年   1篇
  2005年   3篇
  2002年   1篇
  2001年   1篇
  1998年   1篇
排序方式: 共有22条查询结果,搜索用时 0 毫秒
21.
The properties of 100 % PES core-spun threads were studied before and after the sewing process at different stitching speeds, by determination of the threads tensile force during the sewing process and by changes of the mechanical and thermo-mechanical properties after the sewing process. This analytical method is especially advantageous when monitoring contemporary thermal and mechanical effects, as is the case when loading the sewing thread. Loadings during the sewing process cause structural changes in the thread-twisted fibres. This is confirmed by changes in the thermo-mechanical properties after the sewing process. Simultaneously, changes in the threads mechanical properties after sewing were also observed.  相似文献   
22.
Measurements of runoff and infiltration were made at five spatial scales, terracette (<1 m), hummock (10–20 m2), part-slope (1000–2000 m2), slope (1 ha) and catchment (50 ha), on a shrubland and an open forest site. The study was aimed at understanding the relationships between runoff production, vegetation patterns and microtopography at different spatial scales within a sparsely vegetated, semiarid area. The results of runoff monitoring and rainfall simulation experiments showed that runoff did not occur at the slope scale. It was buffered at the terracette level by nonuniform infiltration at the rims of terracettes and at the hummock scale by rapid infiltration under oak shrubs and trees. Slope and catchment runoff were not connected to runoff at these fine scales. The field evidence is discussed within the context of hierarchy theory, and the implications for management of these shrublands are related to maintaining both the vegetation mosaic and runoff on these slopes.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号